While the Queen has probably never carried a shopping bag, you can tell a lot about her from where she buys her wares. Along with Barbour, Hunter and Land Rover are more than 700 companies possessing her Royal Warrant – the right to display her coat of arms. The line-up features all the institutions one would expect a head of state to frequent: from champagne houses to luxury car manufacturers and Waitrose in Bracknell. But the list also reflects a more down-to-earth “high-street” monarch: Carphone Warehouse and House of Fraser possess a Warrant, as do British Gas and Weetabix.

To apply for a Royal Warrant, a company must have been doing business with the household for at least five years. If they are successful, they can advertise the fact by displaying the Queen’s coat of arms. “The Royal Warrant is the ultimate seal of approval,” says Roger Gadd of whip maker Swaine Adeney Brigg. “Our customers definitely take note of it, which is good for business.”

But a Warrant also carries with it responsibilies. Beholders must exercise discretion, and make it their duty not to let standards slip.

Bill Keeling and his half-brother Nick Crean are real-life Willie Wonkas: their chocolates were a favourite of Roald Dahl, author of Charlie and the Chocolate Factory. In a small factory in west London their staff produce more than 200 tons of chocolate each year, including Prestat Dark Chocolate Wafers, which are said to be Her Majesty’s favourite.

Crean used to wonder if the 4lb handmade Easter egg, sent annually as a gift to the Queen, made it past the courtiers, until this year, when he received an urgent phone call from a lady-in-waiting. “It was a week before Easter and I hadn’t got the egg to the post yet,” he says. “The woman on the phone said: 'I’m terribly concerned. Where is our egg?’ ”

The egg made it to Windsor in good time for Easter, and since then Crean has sent Prestat’s special Diamond Jubilee chocolate collection to the Queen, the Duke and Duchess of Cambridge and Prince Harry. “They all wrote thank you letters, which was very motivating,” he says.

Mike Rowland

Wheelwrights and coachbuilders

During the royal wedding last year, coachbuilder Mike Rowland and his son Greg had their eyes glued to the royal carriage, rather than the bride. “I couldn’t help it – it was so fascinating watching it in action, although I did look up when Pippa Middleton arrived,” says Greg.

There’s always a chance that one of the Queen’s carriages will be in for repair at the Rowlands’ workshop in Colyton, Devon, hidden under heavy cloth. “She has more than 100 of them and many of them are used daily to exercise the horses,” says Greg, who is a wheelwright and coachbuilder by day and a fireman by night. “Whenever we’re asked to fix a carriage, we make the job our priority.”

Coachbuilding has been in their family for more than 1000 years. “I’m trying to learn all the traditional skills from father. To use a cliché, you can’t reinvent the wheel.”

Roger Pope & Partners

Dispensing opticians

If you’ve ever wondered where the Queen buys her specs, the answer is Roger Pope’s shop in London. Of course the Queen never visits the shop herself; she trusts Pope to bring an appropriate selection of frames to Buckingham Palace for her to try in front of her dresser.

“I found it very nerve-racking at first but the more I go, the more I relax,” says Pope. He takes to the palace a briefcase containing about 15 or 20 examples of the traditional, two-tone opaque frames that the Queen likes to wear. “They need to be understated,” says Pope. “I’ve got a pretty good idea of what she likes.”

He holds up a pair of specacles with a thin, partially opaque frame. At £175, they’re certainly not the most expensive frames in the shop – diamond-studded varieties cost more than £10,000. “The Royal family are definitely not our most extravagant customers,” confirms Pope.

Swaine Adeney Brigg

Whip and gloves makers

It’s not often that the Queen needs to buy new riding gloves and whips these days, but she is still a loyal customer of leathergoods manufacturer Swaine Adeney Brigg. “The last large order we had was for six postilion’s whips for the royal carriage at the wedding last year,” says Roger Gawn, director of the company. “They’re extremely long enabling the mounted postilion to tickle the carriage horses at the back.”

The company, which has held a Royal Warrant since 1750, also has the Prince of Wales’s Warrant for umbrellas and also carries out repair work for him.

“We’ve got an old suitcase in to be mended at the moment and last year we repaired his sporran,” says Gawn. Tom Williams, manager of the St James shop, hand delivers items back to the palace when they are ready. “Without sounding glib about it, it’s one of those things you get used to,” he says.

Berry Bros & Rudd

Wine and spirit merchants

It was Edward VI’s doctor who cemented the Royal family’s relationship with wine merchants Berry Bros & Rudd when he walked into the shop and asked for a “warming cordial” for the King to drink when he was driving his “horseless carriage”. He was supplied with a bottle of ginger liqueur, which went down so well that the Queen still orders “King’s ginger liqueur” from Berry Bros today.

Not only does the company, which has premises in St James’s Street, hold her Royal Warrant but for the past four years Simon Berry, managing director, has been clerk of the Royal cellars. As such he is head of the Royal Household Wine Committee, which is assigned to taste wines for state banquets.

The committee’s blind tastings take place in the Buckingham Palace cellars, “a wonderful Victorian wine store with iron bins to store champagne at the right angle”, Berry says. Inexpensive New Zealand sauvignon blancs and basic red bordeaux often feature. “The wines must be good, but they don’t need to be show-stoppers,” Berry says.

While the committee chooses the wines, it’s Robert Large, yeoman of the Royal cellars, who selects what will be drunk at specific engagements, making sure that each of the Queen’s Warrant holders gets a chance to showcase. Pol Roger, for example, was the chosen champagne at the royal wedding, while special edition bottles of Moët will be drunk at the Queen’s Diamond Jubilee picnic on June 4 [see Victoria Moore, page 9].

Stanley Gibbons

Philatelists

When George V, the “collector” king, was told by a courtier that “some idiot” had bought a rare Prussian Blue stamp for a record £1,000, he replied: “I can well believe it because I am that idiot.”

The Queen is not as passionate about stamps as her grandfather, but she understands the importance of the enormous collection she inherited from him and relies on stamp trader Stanley Gibbons to ensure every stamp issued with a Royal head on it features in the collection. “New stamps are issued on a bimonthly basis,” explains Keith Heddle of Stanley Gibbons. “This year there will be Jubilee and special edition Olympic stamps for every gold medal Britain wins.”

The Royal household has been trading with Stanley Gibbons since it was founded in 1856 – the same year that the Penny Black was issued by Queen Victoria – and the Queen’s collection is now thought to be the most valuable in the world.

Gordon Bell Pianos

Piano tuning and servicing

Gordon Bell, who runs a piano shop in Aberdeen, tunes the four pianos on the Balmoral Estate on an annual basis, and was awarded the Royal Warrant by the Queen in 2008.

The pianos at Balmoral “aren’t played an awful lot”, but Bell takes his appointments at the castle very seriously: the day before he has his trousers “nicely creased”, his shirt ironed and his car valeted. “I take a lot of pride in going up for that appointment. It means a lot to me and I get a bit nervous,” he says.

The occasion is especially daunting when the Queen is in residence. “The last time she spotted my van and mentioned my name – I was very glad it was nice and clean,” he says.